Leinster manager Guy Easterby described Saturday's seven-try rout as a wake-up call to the senior players on duty.
But he added that while a side never likes to stomach a 43-0 defeat, it was good that so many young players got experience against a near full-strength Northampton side.
“We just didn't make the progress we intended in the game. But it's good for young players to experience this level and see where they need to get to.
“It's also a bit of a wake-up call for some of our senior players who were on duty. We need to improve ahead of the opening (Pro12) game against Scarlets,” he said.
Leinster will conclude their pre-season fixtures away to Sale Sharks next weekend, and Easterby said they would be looking for a big improvement.
“We just did not bridge the gap against Northampton and they just pulled away from us.
“It was warm and the crowd were red-hot and we just did not get up to the required level.
“But it wasn't all negatives. It's great to get game-time under your belt, there weren't any injuries and players will learn from this sort of experience,” added Easterby.
Joe Schmidt's side had a decent opening quarter, but three ties before the break saw Northampton pull away.
Leo Cullen, Richardt Strauss, Isaac Boss and Devin Toner all made their first starts of pre-season, but the Blues leaked another four tries in the closing 13 minutes.
Northampton crossed after 23 minutes when Dom Waldouck was on hand to barge across the line, despite the efforts of Andrew Boyle, who was forced off injured as a result.
Six minutes later the Leinster line was breached once again; this time left winger Paul Diggin did the damage, and once again Ryan Lamb failed with the difficult conversion as the Saints led 10-0.
Ex-Blackrock College and UCD flyer Vasily Artemyev got their third at the end of a good move for Northampton to lead 17-0 at half-time.
Both sides emptied their benches but it was Northampton who finished strongly, with Scott Armstrong, Tom Wood, Tom May and Noah Cato crossing in the final quarter.
Elsewhere, Connacht coach Eric Elwood said this pre-season 45-11 hammering at Harlequins on Saturday will have no bearing on the sides' Heineken Cup clashes this season.